FMIC is this true

[jevansio]

Some good points raised there, some might also have said, If having a CC would have a benificial effect "TOYOTA would have used one", but may not be considering engine builders surely have to keep to budgets, reduce the number and expense of components to minimum needed to do the job sufficiently and also for reliability, but not necessarily without scope for improvement.

RE Toyota using one, funny thing is they did use one on the GT4 , they didn't twin it up with another intercooler though

[Wez]

How about using the stock IC location for the CC rad, you could fit a nice sized one along with the pump in that area and then fitting a long CC where the bottom pipe run goes under the rad?

 

Good/bad idea, what would be more efficient?

[Stevie Boy]

On the other side they don't have to be low key, they can be bling & have just as much bhp potential (the Precision core I bought for my old MR2 was rated at 900bhp, they are prodcuing them well over that now). I never got round to installing the system (only buying the parts), Dan the lad who I sold the car to fitted it.

 

Pic for ya:

http://i191.photobucket.com/albums/z211/Gee_Man-23/04062007305.jpg

 

And the prerad:

http://i191.photobucket.com/albums/z211/Gee_Man-23/04062007309.jpg

 

Thats another thing i tried to comprehend, all the aftermarket CC set ups i've seen have been far from unintrusive of "bling", OK so Laminova style heat exchanger may be kept discrete for fluid/oil to water cooling, but air to water cores tend to be pretty large (all be it not as "huge" as air to air).

[jevansio]

How about using the stock IC location for the CC rad, you could fit a nice sized one along with the pump in that area and then fitting a long CC where the bottom pipe run goes under the rad?

 

Good/bad idea, what would be more efficient?

That would be my preferred choice for the rad location, don't think there's anywhere else it could feasibly go.

[Wez]

That would be my preferred choice for the rad location, don't think there's anywhere else it could feasibly go.

 

I guess this would be the perfect location as you could utilise all that great ducting for the CC rad.

[Stevie Boy]

RE Toyota using one, funny thing is they did use one on the GT4 , they didn't twin it up with another intercooler though

 

I'm far from rubbishing the idea, as they're not the only manufacturer to use CC systems either.

 

For example on Jag XJ&XK 4.0/4.2 V8 supercharged engines, Jag used CC to cool the compressed air, but say on a Mini Cooper S they went for air to air with ducting in bonnet, surely reinforces the fact that car/engine manufacturers use what they deem an efficient and i'd expect most cost effective method of doing the job, but surely not the be all and end all method.

[Chris Wilson]

Air to water is often used on mid engined cars due to the problem of getting a decent air flow in and out of a mid mounted air to air I/C. Lotus used one on the esprit Turbo, for example.

[Suprash]

Well this was a interesting read.........and I wont comment with my limited knowledge, but I will say with my FMIC I suffered overheating issues on sunny days, but since dropping in a thicker rad the engine temps have been ok........

 

Also one more point, people talking about the position of the SMIC being good as its in the wheel arch and the momentum of the turning wheel causes a lower pressure behind the SMIC drawing more air through.......

 

Does the stock fan not produce a similar effect being sat behind the rad and FMIC.....?

[TLicense]

Well this was a interesting read.........and I wont comment with my limited knowledge, but I will say with my FMIC I suffered overheating issues on sunny days, but since dropping in a thicker rad the engine temps have been ok........

 

Also one more point, people talking about the position of the SMIC being good as its in the wheel arch and the momentum of the turning wheel causes a lower pressure behind the SMIC drawing more air through.......

 

Does the stock fan not produce a similar effect being sat behind the rad and FMIC.....?

 

It's not the wheel turning that creates the lower pressure although that does have some aero effect. It's the fact that you basically got a large expansion (in fact it's an infinite expansion as the wheel well opens to atmosphere) this draws the air through.

 

The stock fan, whilst effective will I imagine have it's performance greatly reduced by increasing the thickness of radiators / IC's in front of it.

[TLicense]

Although slightly off topic, but still kind of relevant to the discussion of rads and IC's. With oil coolers, there is another phenomenon that you have to be VERY careful about called "coring".

 

This basically happens when you have a long cooler. As the oil travels along the core, it's temperature drops. If it's drops too much, the viscosity of the oil drops, which causes the flow of the oil in the core to slow. As the velocity of the oil slows, it is cooled more by the air flowing through the core, which cools it further. Eventually you end up with a very slow flow, or no flow at all. This has the effect of basically reducing the size of the cooler, as the oil flows around the "cored" rows.

There's a couple of ways to stop this from happening. The first and most important way is to use a correct length core so that the exit temperature isn't too low.

As the length of cores are generally fixed, one way to get around it is to blank some of the core off using tape. This effectively reduces the length of the core.

Lastly you can heat the last bit of the core. This is obviously quite tricky to do within the MKiV application, but is often done on race cars if the ambient temperatures are low and the car isn't up to temp yet.

 

If left unchecked you could conveivably end up with a blocked oil system, which could cause overheating and high oil pressure issues.

[mattanna]

I am no expert but i would not bother with an fmic when you could get an uprated ARC smic, which will apparently out perform most fmics, they are well over a grand though, which is why a lot opt for Greddy fmic's etc, singles etc then a good fmic i suppose, not worth doing on the cheap, and not worth doing at all if staying standard

[Gazboy]

How does the air exit after the upgraded thicker radiator? Doesn't it just tumble down infront of the block then under the car? What effect do vented bonnets have in this respect, and would it be better to have a dedicated ducting track leading from the back of the radiator to these vents?

[Suprash]

It's not the wheel turning that creates the lower pressure although that does have some aero effect. It's the fact that you basically got a large expansion (in fact it's an infinite expansion as the wheel well opens to atmosphere) this draws the air through.

 

The stock fan, whilst effective will I imagine have it's performance greatly reduced by increasing the thickness of radiators / IC's in front of it.

 

Thats odd as Im sure I remember reading some gumth from Toyota or somewhere quite official that the reason the SMIC was placed in front of the wheel was because the turning of the wheel draws air back, creating a low pressure drop behind the SMIC, just goes to show that even stuff you read on tinternet aint always true..........

[JohnA]

On the 'parallel' issue, I am of course aware of the principles involved.

 

In the supra's case the chargecooler would be in *series* though.

 

The added pressure drop will be negligible, remember it only handles the excess heat that made it through the SMIC, so the heat -exchanger will be modestly sized (what would be sized normally for a 200-300bhp car maximum - and that is generous!)

 

As a result it won't have the full temp difference that the SMIC does, so it won't operate as efficiently as a heat exchanger would like. But in this design we try to give full advantage to the SMIC, as we try to expel as much heat as possible outside the engine bay. (the chargecooler will be shedding heat in the engine bay if it's rad is situated up front)

 

I have actually done a similar setup on a C20LET engine with a FMIC an a chargecooler. The difference was 10-15C with the chargecooler in the summer and practically nil in the winter.

 

Yes, you add complexity and more things to go wrong for a slight increase in intercooling, but that has to be set against a very disruptive FMIC installation that mucks up all the airflow upfront and sheds all the heat in the engine bay.

[Wez]

What would you recommend for a complete Charge Cooler setup, ie no SMIC or FMIC, the SMIC location could then be used for the CC rad.

 

What would you need for say a 900hp application?

[JohnA]

Wez, these are OK for drag setups where they fill the tank with ice etc.

 

In real-life driving under boost you create a lot of excess heat that the water has to absorb and then get rid of. After a series of full-boost runs, if they are close together, you can end up with a lot of heatsoak and risk damaging the engine instead of intercooling it.

 

That's why I'd prefer to have the SMIC handling most of the 'bread-and-butter' heat, with the chargecooler only kicking in when there is abnormal heatload.

 

For a 900bhp application on a street car, I'd go for a FMIC though

[Wez]

OK thanks.